Devices that detect light are used in many applications and variations. In addition to solid state imagers like CCD (charge coupled devices) imagers or CMOS (Complementary Metal Oxide Semiconductor) imagers which are capable of providing 2D (2 dimensional) images, 3D imager, depth imagers, range finders etc are becoming increasingly popular for multiple applications. Applications include for example the taking of a profile of objects or environments, the determining of an object distance, the tracking and recognition of objects to the recognition of movements or gestures by human objects.
In solid state photo conversion devices such as semiconductor imager devices, incoming light is converted into charge carriers of positive type (holes) and negative types (electrons). In many applications the transfer of charge carriers of one or both types to predetermined areas such as a read-out node is crucial to the operation of the imager.
In the manufacturing process of some imager devices, gate structures are formed laterally spaced apart by gaps. Between the gate structures, manufacturing steps such as spacer and/or liner are formed. The processing of the spacer or liner as well as other processes typically provides damages to the surfaces of the substrate. This causes increased trapping and recombination as well as other adverse effect on the charge transfer.
It is therefore beneficial to have a device manufactured such that the transfer of photo-generated charge carriers is provided in a more efficient way.